The present invention relates to a drying apparatus and, more particularly, a drying apparatus wherein moist air discharged from a drum in which materials to be dried are housed is passed through a heat exchanger to remove moisture and then again supplied into the drum.
The drying apparatus of this type has an outer box and a drum arranged rotatably in the outer box and housing therein materials to be dried, such as underwear, for example, wherein materials are dried by supplying hot air into the drum. The drying apparatus also has a heat exchanger arranged in the outer box and moist air discharged from the drum is passed through the heat exchanger and then again supplied into the drum after its moisture is thus removed. The conventionally well known drying apparatus employs a pipe type heat exchanger having a plurality of pipes through which air discharged from the drum is passed, and a plurality of radiating fins fixed by welding to pipes. However, the pipe type heat exchanger type becomes complicated in construction and needs troublesome weldings, thus making the assembly capacity low and the manufacturing cost high. In addition, water drops formed on the inner surfaces of pipes in the heat exchanger flow in a direction reverse to the direction in which air flows through pipes, so that water drops are pushed back by air flowing through pipes. The pipe type heat exchanger therefore has a low drain efficiency for water drops, which causes the pipe type heat exchanger to exhibit a low moisture removing efficiency.